The present invention relates generally to sample collection and drug delivery systems, and more particularly to sample collection and drug delivery systems for freely-moving laboratory animals.
Most animal studies in physiology, and many in pharmacology and basic biology, require samples (e.g. blood or cerebrospinal fluid (CSF)) to be removed for analysis, some sort of electrical activity to be monitored, and/or drugs to be administered at precise times. If such experiments are to be conducted in alert, freely-moving animals, which is generally preferred, some sort of tether encasing the fluid or electrical connections to the animal is normally required. To allow improved freedom of movement, a swivel is generally provided between the animal and the sampling or infusion device. Multichannel electrical swivels may be reasonably satisfactory (although mercury-based devices are hazardous), but fluid swivels are often problematical, being stiff and subject to leaks and blockages. This restricts the animal's movement and requires frequent experimenter intervention to remove twists from the tether. The result is that the ideal of a stress-free environment for the animal under study is difficult or impossible to achieve with currently available equipment.
There is no commercially available equipment that provides the capability of multichannel fluid sampling and/or administration in alert, tethered animals. However, an alternative method for achieving multichannel sampling has been published (See Matsumura, H., Kinoshita, G., Satoh, S., Osaka, T. and Hayaishi, O., "A novel apparatus that permits multiple routes for infusions and body fluid collections in a freely-moving animal," J. Neurosci. Methods 57 (1995) 145149). In that system, the rat itself, rather than the supporting equipment, is moved on a turntable to reduce the twisting of the tether. This approach is undesirably stressful to the animal and presents other problems.
The present invention is therefore directed to the problem of developing a sample collection and drug delivery system with a unique multichannel capability for use with alert, freely moving laboratory animals, without putting any additional stress on the laboratory animal.